Distended fibrous product



;, as saponin which, under Patented July 17, 1934 msrannan ruinousraonuo'r 4 Frank L. Bryant, Chicago, 111., asslgnor to CellufoamCorporation, Chi

, of Delaware cago, 111., a corporation No Drawing. Application March10,1932, Serial No. 599,329

zs'cmma (1192-21) The product of the present invention constitutes amodification or variation of the product produced in accordance with themethod set forth and described Bryant Patent No. 1,740,280, 5 issuedDecember 17, 1929, and the present application is in part a continuationof application Serial No. 569,349, filed October 16, 1931, and isdirected to the'distending of fibrous materials which have beensubjected to a preliminary hydrating treatment, for alength of time andunder proper conditions,to gelatinize the surfaces of the fibers to asuilicient extent to cause the fibers to more intimately engagejandadhere to one another when subjected to the distending treatment setforth in,the Bryant Patent No. 1,740,280 aforesaid, with the result thatthe final product will'possess a greater measure of stability and'willbetter maintain its distended con- Y dition by reason of the embedmentof the ge- Q0 latiniz'ed surfaces of the fibers in one another.-

The Bryant Patent No. 1,740,280 aforesaid, relates to the distending offibrous materials by formation of a mixture of fibers and water, withthe addition of bubble-forming ingredients such agitation, will producea relatively stable foam and serve to hold the fibers in distendedrelation to one another durin the drying operation, which results in theformation of a light fluffy or fibers of which, when dried, are helddistended merely by their intermeshing or interweaving. By the method ofthe present invention, the surfaces of the fibers themselves aregelatinized so that when distended they will become more permanently setor interlocked with one another and at the same time the softening ofthe fiber surfaces better conditions them for a fireproofing orwaterproofing treatment or for a dyeing process, since the softenedsurfaces of the fibers 40 will better hold and retain the ingredientsemployed in such proofing or dyeing treatment.

In particular, the product of the present invention is intended for useas an insulating agent against heat transfer in buildings or in domesticand industrial equipment such as refrigerators, driers and the like,passenger and refrigerator equipment for railroads, automobiles,airplane cabins, and numerous other applications in which insulatingmaterials such as fiber board, cork, mineral wool, hair, grass, etc.,have customarily been used. These materials differ widely in insulatingvalue. and in physical characteristics; and in many instances it isnecessary to sacrifice insulating value for strength or otherconsiderations. The insulating value of an important factorconsideration in providing for the framing of the cottony product, the

.of imparting color or depending upon the material depends primarily onits density, those materials having the lower density usuallypossjessing the higher insulating efliciency. Among' other properties whch influence the value of material as an insulator, is the conduc- C3tivity of 'the material itself and the arrangement of the particles withrelation to the resistance which they tend to offer to convectioncurrents.

The weight, also, of the materials employed is which must be taken intostructure which is-to be insulated, and the use of certain materialspossessing high insulating value, such as hair and cork, is frequentlyprohibited byreason of their high cost.

The product of the present invention possesses high insulating value byreason of its distended formation and by reason of'the fact that thematerials of which it is composed are poor conductors of heat; and themethod employed in producing the material is one which gives 'to itsufficient stability and stiffness and resistance to compacting actionto render its use advantageous in numerous instances where insulation isrequired, either with or without a treatment which renders it fireproofand/or waterproof.

In producing the productof the present invention, it is preferred toemploy cellulose fibers which are preliminarily subjected to a beatingor hydrating action, as set forth and described in application SerialNo. 569,349. The beating or hydrating of the pulp converts the exteriorsurfaces of the fibers to a somewhat gelatlnized condition, and in thiscondition the surfaces are more susceptible to treatment with substancescapable fireproof or waterproof instance, pulp fibers are introducedinto a regular paper stock beater of the Holland, Niagara or Jordantype, with sufficient water to give the proper consistency (about 3%),and subjected to. the action of the beater for a sufilcient length oftime to produce the desired degreeof hydration. This period may bevaried, condition of the raw fibers and upon the extent of thegelatinizing effect desired, but for most purposes a treatment of anhour will serve to give to the fibers the desired degree of hydration.

The hydrating action herein referred to, is to be distinguished from anaction which results mere- 105 ly in the breaking up of the relativelylonger. fibers into shorter lengths, but without material softening ofthe fibersurfaces to produce the gelatinizing effect which is essentialin the method of the present invention, and which substantially noproperties thereto. For

modifies the surface condition of the fibers and their capacity to embedthemselves into one another at the points where they contact orintersect when held in distended relation and in mesh formation to oneanother.

After the fibrous materials have been sufiiciently beaten and hydrated,it is necessary to incorporate with the liquid mixture a suitablequantity of bubble-forming or foam-forming ingredients of the characterset forth and described in Bryant Patent No. 1,740,280 aforesaid. It mayalso at this stage be desirable in proper cases, to incorporate with themass a quantity of hair or other fibrous material which it is desiredto; introduce into the completed product. Experience has shown that theincorporation into the mass, of an amount of hair equal in weight to 50%of the cellulose or other fibrous material contained in the liquidmixture, will produce a highly desirable product having greater elementsof strength and resistance 'to compacting, although it will beunderstood that the introduction of such materials as hair or the likeis optional.

The foam-forming ingredient which is preferred is saponin, which may beadded in the proportion of substantially one part of saponin to 400parts of water in the mixture, and after the addition of the saponin orother bubbleforming ingredients, the mixture, either with or without theaddition of proofing agents, is subjected to agitation in the manner setforth in the Bryant Patent No. 1,740,280, for a sufiicient period tocause the mass to expand and assume a foamy condition through the actionof the bubbleforming or foam-forming ingredients, and until the mass hasexpanded to about two and onehalf times its original liquid volume anduntil the hair or other material, if any, which has been added to thecellulose fibers, has become thoroughly impregnated with and evenlydistributed throughout the mass.

After the material has been brought to a foamy or creamy state, due tothe presence of the minute bubbles formed therein, it is discharged inthe form of a layer and dried either on the moving surface of aFourdrinier machine or in molds, or in any other suitable manner.

During the drying operation, the layer of material may have formedthereon a surface skin or coating, produced in the manner set forth anddescribed in Byrant Patent No. 1,841,785, granted Jan. 19, 1932, whichresults from the momentary application of a somewhat heavy suctionapplied to the surface of the layer, which has the effect of compactingthe exterior surface fibers of the mass in such a way as to produce aclose textured paper surface, but without, however, subjecting theinterior of the layer to such compacting action as pointed out in detailin the patent last referred to. The production of such a closelytextured paper surface is materially facilitated in the present instanceby reason of the gelatinized condition of the fibrous surfaces due tothe preliminary hydration to which the fibers were first subjected. Thesoftening of the fibers causes them to more intimately unite or cbalescewith one another on the surface when subjected to the close compactingaction of a suction, with the result that products formed from thepreviously hydrated fibrous material, when subjected to the actiontending to produce a surface skin or layer, will have formed thereon amore closely knit or integrated surface skin which is bonded or unitedto the interior of the layer more closely or intimately than in casesnently retain its distended condition as a result of the softening ofthe fiber surfaces produced by'the preliminary hydrating treatment.

Furthermore, theformation of the closely textured skin surface on one orboth sides of the layer will add toughness and coherence to thecompleted product, so that for many purposes it will not be necessary toenclose the product in a paper sheath, adhered or otherwise securedthereto, in the manner at present customary in the production of layersor sheets intended for insulating purposes.

Furthermore, the intermeshing or coalescing effect produced as a'resultof the gelatinizing of the fiber surfaces, results in a more intimateunion of the fibers throughout the entire layer, so that there is littleor no tendency for the paperlike surface layers to become displaced ortorn away since the surface fibersare intimately anchored and unitedwith the underlying body fibers in a permanent union.

Layers of materials produced in the manner described possess sufiicientrigidity and stiifness to enable them to be cut, shipped and utilizedafter the manner of fiber board or similar materials, and although thelayers of the present invention are sufiiciently rigid andself-sustaining to permit ready manipulation, they are neverthelessextremely light and porous in texture and possess high insulatingproperties.

The sheets or layers above described, especially when produced in themanner to afford a closely textured paperlike surface skin, may bereadily subjected to a proofing surface treatment with wax, asphalturnor other materials commonly employed for proofing surfaces, since theclose texture of the paper surface renders such a treatment easy andadvantageous. However, for many purposes, it may be desirable to subjectthe fibers, either preliminarily or concurrently with the foamingoperation, to a fireproofing or waterproofing treatment, so that thecompleted layer throughout will be either fire-resistant orwaterresistant. The gelatinized condition of the fiber surfaces renderssuch a fireproofing or water= proofing treatment peculiarly advantageoussince hydrating has been the softening of the fiber surfaces produces aconform a protective coating. Proofing substances may be employed whichwill fuse or melt at temperatures less than the temperatures requiredfor drying, but will not fiux onto the fibers while they are in a wetcondition, due to the water coating on the individual fibers, whichprevents the adherence of the proofing material thereto. It isessential, therefore, that the temperature be higher than the fusiontemperature of. the water repellentproofing"--substance, or the mass maybe dried at temperatures below the fusion point of such substance, andthe material may thereafter be subjected to temperatures sufficient tocause a fiuxing of the waterproofing materials.

For the above purpose, such materials as wax, resin, asphaltum, and somesalts of fatty acids, are recommended. Such materials are introduced ina finely divided state into the foaming solution with the fibers, andthe whole whipped or agi-t tated to incorporate the air necessary toform a stable foam, as previously set forth.

The method of reducing wax, resin, asphaltum, etc., to a fine state ofsubdivision is by converting them into emulsions .with water and adispersing agent, and then breaking the emulsion in order to releasesuch finely divided particles, by the addition of some setting agent,such as an acid or acid salt. Such an emulsion may be added to thefoaming solution with the fibers and the setting agent, and then foamedby agitation, or the emulsion may be added to the foaming solution withthe fibers 'and then whipped toform the foam, after which thesettingagent may be added.

In lieu of the above, the setting agent may be added to a dilutedsolution of the emulsion and the formed precipitate added to the foamingsolution with the fibers and then whipped to form the foam. Emulsionsare also available whichwhen diluted with large amounts of water have vthe effect of breaking down without the addition of 'a'setting agent,and these may therefore be added to the foaming solution and the fiberswithout employing a setting agent. It is also possible to dissolve thwater repellent or proofing agent in a non-aqueous miscible solvent,which when diluted with water will throw out the finely dividedprecipitate of insoluble water repellent. V

-For example, resin may be dissolved in alcohol, the solution introducedinto the mixture-of foam-forming solution and fibers, and the masswhipped to form a stable foam and afterwards dried at a temperaturesuflicient to flux the resin onto the fibers.

Solubl salts of some of .the fatty acids. such as sodium stearate, orsodium resinate, may-be introduced into the mixture, of water and fibersand foam-forming chemicals, and'the coating is formed onto the fiberseither during the foaming period or thereafter,-in an insoluble form bythe addition of metallic salt capable of reacting with .Asan example ofthe above method, I may use a soluble sodium stearate, which, afterbeing mixed with the other ingredients, is converted into an insolublezinc stearate by the addition of zinc chloride. In like manne g-a sodiumresinate may be used and convertedin'to aluminum resinate by theaddition of aluminum sulphate.

As a detailed example of a waterproofing treatment by the use of sodiumstearate, I employ the followingmethod:

Take approximately 150 parts of pulp on an' air dried basis, 4700 partsof water, 15 parts of sodium stearate dissolved'in the water, 4 partsofzinc chloride required to convert the soluble sodium stearate into aninsoluble. zinc stearate, and thoroughly distribute it throughout thefibers in the water, to which mixture is added 10 parts of saponin, andthe wholewhipped to incorporate the air and form the stable foam inconbut in other cases it may a separate step in the operation,

, formity with the principles set'forth in the Bryant patent aforesaid.The proofing ingredients and the saponin can be mixed separately, or canbe incorporated and all mixed together during the foaming operation. a

As an alternative to the above method, the foam-forming agent may beadded before the zinc chloride, the, mixture may soluble zinc stearate.

be foamed, and then the zinc chloride added to precipitate the inaAccording to the above technique, the proofing and foam-forming steps inthe process are either partly or wholly combined into a singleoperation, which in many cases may be most desirable,

be found-better to pretreat the fibers in advance of the foam-formingoperation, and under such conditions the addition of the saponin may bedeferred until the waterproofingoperation has been completely performedby the transformation of the sodium stearate into zinc stearate, afterwhich, and as be added and the proofed fiberswhipped to distend them andgive to the product the physical characteristics set forth and describedin the Bryant patent aforesaid.

As a detailed example of the use of sodium resinate for waterproofingthe fibers, the following example is given:

Take approximately 150 parts of pulp on an air'dried basis, in 4700parts of water to which sodium resinate is added in the proportion offrom two to five percent of the weight of the fibers. ,Sufiicient alumis then added to precipitate the sodium resinate 'as'aluminum resinateby rendering the solution slightly acid. To the above solution ten partsof the foaming agent are added and the mixture agitated and foamed inthe manner previously. -described. If desired, the proofing agents andthe foaming agent may be added separately, or all of the ingredients may"be combined and foamed together in a single operation.

If desired, the, pro fing step in the operation may be completelyperformed as a'pre-treatment, after which the proofed. fibers may befoamedand distended in the manner previously deance with methods wellunderstood'in the paper. I Y

industry.

The degree of water resistance is controlledby the amount and type ofwater" repellent used. four to six percentof the weight of the air driedfiber being suflicient in the case of wax to reduce .the watercapillarity to approximately zero.

Where asphaltum'isused, approximately 15 to 20 percent of the weight ofthe air dried fiber is required toproduce a like result.

Although in many cases it is whether the fibers be pre-treated-with aproofing substance and afterwards subjected to the foaming operation, orwhether the proofing and foaming operations be performed concurrently,

nevertheless, it will be found that in some cases a pre-treatment forproofing is desirable inorder that the precipitating of the waterrepellent substance upon the fibers may not be deleteriously and thenrendered insoluble by theuse As a further alternative, finely I thesaponin may immaterial ,shape,.remove the excess solution, and dry theformer massof fibers at temperatures sufiicient to cause a fiuxing ofthe minute wax particles onto the fibers to form a waterproof coating orcovering for each fiber.. In the above process it will be noted that thefoaming and waterproofing steps are concurrently performed in a singleoperation, which is desirable from the standpoint of economy in caseswhereother considerations do not indicate the necessity for performingthe steps separately.

Where it is desired to fireproof the fibers, a similar technique may beemployed and the operations performed either in sequence or concurrentlyin most cases. Fireproofing or fiameproofing is generally considered tobe caused, first by the fireproofing agent melting at temperatures lessthan the ignition temperature of the material, and thus coating thesurfaces thereof with a film impervious to air; second by the liberationof gases which mix with those produced from the heated fibrous materialand render them noninfiammable; and third by endothermic changes whichare responsible for the lowering of the temperatures below that requiredfor ignition.

' In the'fireproofing of the present materials, it will be understoodthat the term proofing is employed in a relative sense and is intendedto cover any treatment which increases the fire resistance of thematerials to a substantial degree. The fireproofing may be attained bythe addition of proper quantities of the desired chemicals, such asaluminum chloride, ammonium sulphate, ammonium phosphate, borax, boricacid, or other well known fireproofing salts, either singly or incombination, into the mixture of the foam-form ing ingredients andfibers, which are then whipped to form a stable foam, and formed intothe desired shape and dried in the manner heretofore described.

In lieu of the above treatment, the fireproofing step may be performedas a preliminary'step or pre-treatment before the fibers are subjectedtothe foaming operation, in which latter case the foaming operation willbe performed on amass of proofed fibers instead of upon a mass of rawfibers as in the case of the Bryant patent previously referred to. a 7

As an example of pre-treatment of the fibers by the use of aluminumchloride, the following, -is given:

To approximately parts of pulp on an air dried basis add 4700 parts of asaturated solution of aluminum chloride, which serves to fireproof thefibers to a substantial degree. The fibers thus fireproofed may besubjected to the foam-forming operation and dried in conformity with themethod previously set forth to produce 7 a fire proof product.

In'lieu'of the pre-treatment above described, the foam-formingingredient may be added to the pulp in suspension in the aluminumchloride solution and the mass as a whole subjected to vducecl bubbles.

the foam-forming operation and thereafter dried in a single operatic Asa second example of a fireproofing operation, which I prefer in certaincases, I take a slurry of fibers with water, to which is added afoam-forming ingredient such as saponin, together with 15 parts ofborax, 6.5 parts of boric acid based on the weight of water used, thewhole being whipped to form a stable foam with the'fibers incorporatedtherein, and afterwards formed to shape and dried in the mannerpreviously described,

It may also be desirable to color the materials made by this process,and this may be accom-- plished by introducing into the mixture offibers and foam-forming solution a color pigment or dye, either in thepresence of fireproofing or waterproofing agents, 'or'without them, asdesired, in sufiicient proportions to give the desired depth ofcoloration. For instance, to 150 parts of fibers add 4700'parts ofwater, and with 10 parts of saponin I add 1.5 parts of direct dye, afterwhich the mixture is foamed, formed and dried in the manner previouslydescribed.

While I have endeavored to point out in detail a number of differentmethods which may be employed in producing a product having the desiredcharacteristics, it will be understood that it is not my intention inthe appendedclaims to limit myself to the details of any one or more ofthe processes described by way of exemplification, 10 since Icontemplate numerous modifications in detail and within the scope of theclaims appended hereto.

I claim:

1. The process of treating fibrous material in 0 the production of adistended fibrous product which consists in first hydrating the fibrousmaterial to partially gelatinize the surfaces of the fibers, and inthereafter incorporating with the fibers of said material a chemicalagent adapted to produce a foam and to hold said fibers in distendedrelation during the drying of a product.

2. The process of treating fibrous material in the production of adistended fibrous product which consists in first hydrating the fibrousmaterial to soften and gelatinize the surfaces of the fibers, and inthereafter distending the fibers through the introduction between thefibers of an agent containing relatively stable chemically in- 3. Theprocess of treating fibrous material in the production of a distendedfibrous product which consists in softening the surfaces of the fibersby a gelatinizing process and in introducingan agent adapted underagitation to produce relatively stable bubbles, in agitating the mixtureto produce a foamy condition, and in drying the mixture while the fibersare in a distended condition. I

4 The process of treating cellulose fibers which consists in hydratingthe same to gelatinize the surfaces of the fibers, mixing the same witha foam-forming ingredient, agitating the mixture to form a foamy massand drying the mixture.

5. The process of treating cellulose fibers which consists in subjectingsaid fibers to'a gelatinizing process,'mixing the same with a saponinsolution, agitating the mixture to f rm 9. foamy mass. and drying saidmixture. r

6. The process of treating cellulose fibers which consists in subjectingthe'fibers thereof to a gelatinizing treatment to soften the surfaces ofthe fibers, introducing an agent capableunder agitation of producingrelatively stable bubbles throughout, agitating the mass to produce afoam,

' tating the mixture to form bubbles throughout the mass, and drying themasswith 1 subjecting the fibers, v to an-action' tending-to compact thesurface fibers in formation with a closely textured surface skin.

including the fibers,

throughout the mass, drying subjecting a layer ofthe foamy mass to anaction tending to coalesce the surface fibers in the formation of aclosely textured surface skin, and drying the layer with the skin formedthereon and with the fibers of the body of the layer in distendedrelation.

7. The process of treating cellulose fibers which v consists insubjecting the fibers thereof to a gelattreatment to soften-the surfacesof the fibers, introducing an agent capable under agitation of producingrelatively stable bubbles throughout, agitating the mass to produce afoam, including the fibers, subjecting a layer of the foamy mass tosuction sufiicient to coalesce the surface fibers in the formation of aclosely textured surface skin, and drying the layer with the skin formedthereon and with the fibers ofthe body of the layer in distendedrelation.

8. The process of treating fibrous material in the production of a.distended fibrous product which consists in subjecting the fibrous to agelatinizing process in a liquid bath to soften the surfaces of thefibers, subjecting the fibers to a water proofing treatment, distendingthe fibers by the use of a foaming agent capable of forming a foam inthe presence of the proofed fibers, agidistributed the fibers indistended relation to one another.

9. The process of .treating fibrous material in the' production of adistended fibrous product which consists in subjecting the fibrousmaterial to a gelatinizing process in a liquid bath'to soften thesurfaces of the fibers, subjecting the fibers to distending the fibersing a foam in the presence a itating the mixture to form bubblesdistributed I the mass with the fibers in distended relation to oneanother, and in during the drying operation,

- 10. The process of treating fibrous material in the production of adistended fibrous product which consists in subjecting the fibrousmaterial to a gelatinizing process in a liquid bath to softenthe'surfaces of the fibers,'subjecting the fibers to a water proofingtreatment, distending the fibers by the use of a. foaming agent capableof forming a foam in the presence of the proofed fibers, agitating themixture to form bubbles distributed throughout the mass, drying the masswith the fibers in distended relation to .one another,-and in subjectingthe fibers, during the drying operation,

the surface fibers in formation with a closely textured surface skin.

11. The process of treating fibrous material to produce a distendedfibrous product which consists in subjecting the fibers in a liquid bathto a gelatinizing process adapted to soften the surfaces-of the fibers,chemically water proofing the fibers by the addition of a chemicalagent, add- .ing a foam-forming agent adapted under agita-' tion toproduce a foam. containing relatively sta- I ble bubbles, agitating themass-to .distend the fihersandv produce a foamy mass, and drying themass in=1ayer form and with the proofed fibers in distended relation toone another.

12., The process of treatingcellulose fibers 3 which consists insubjecting the fibers mixed'with, water,- to a hydrating treatment inizethe surfaces of the vfibersyadding thereto a foam-forming ingredient,adding wax inthe material faces with to sufficient suction to compact Yfibrous product in adapted to gelatadequate to cause fiuxing of the waxonto the gelatinized surfaces of the fibers-to form a waterproofcoating. 1

13. The process 0 treating'fibrous material to produce a distendedproduct which consists in subjecting the fibers and water to a hydratingtreatment adapted to gelatinize the surfaces of the fibers, addingthereto afoam-forming ingredient, adding wax previously precipitated byacid, whipping the whole to form a stable foam with the fibers andwaxdispersed therein, removing thefibrous wax adhering to thegelatinized surfaces of the. fibers,'drying the mass and sub-f jectingthe fibers to a temperature adequate to cause fiuxing of the wax' ontothe fibers to form a waterproof coating.

14. The process of treating fibrous materialsto produce a distendedproduct which consists in forming a mixture of'fibers and water,treating gthe mixture to a process adapted to gelatinize the surfaces ofthe fibers, adding thereto a foamforming material and borax and boricacid, whip- .ping the wholeto form a stable foam with the fibersincorporated therein, and drying-the foam to form a fireproofeddistendedproduct.

15. The process of treating fibrous material to produce a distendedproduct which consists in' forming a mixture of fibersandwatensubjecting the mixture to a hydrating action adapted togelatinize the surfaces of the fibers, adding therer to afoam-formingmaterial, adding a dyeing ingredient adapted to (hie-thegelatinized surfaces foam with the fibers incorporated therein, anddrying the foam to produce a dyed distended product.

16. As an article of manufacture, a distended fibrous product having thefibers thereofheld in open intermeshing relation to one another byadherents of the gelatinized surfaces of the fibers.

17. As an article of manufacture, a distended fibrous product composedof fibers having their surfaces gelatinized and treated with a water Aof the fibers, whipping the whole to form a stable proofing agent andheld in open mesh formation by the embedment of the gelatinized fibersurone another at the points of intersection.

'. 18. As an article of manufacture, a distended fibrous productconsisting of fibers having their surfaces gelatinized and the bodyfibers being held in open mesh distended relation by the em- 'bedment ofthe gelatinized surfaces at the points of contact, and having a skinsurface formed by the close compacting of the gelatinized surfacefibers.

19. As an article of-manufacture, a distended fibrous productconsistin'g of fibers having their surfaces gelatinized and the bodyfibers being held in open mesh distendedrelatiou by. the embedment ofthe gelatinized surfaces at the points of contact, and having a skinsurface formed by the closev compacting of the gelatinized surfacefibers, the fibers having a waterproofing agent applied-thereto.

20. As an article of manufacture, a distended the form-of a dried layer,having the surface texture-of the fibers modified as aresult of agelatinizing action, the fibers being held in open'mesh distendedrelation to one andisplaced by the gelatim'zing action.

21. As an article of manufacture a distended fibrous product in the formof a dried layer, having the surface texture of the fibers modified as aresult of a gelatinizing action, .the fibers being held in open meshdistended relation to one another by the coalescence ofthe surfacematerials displaced by the gelatinizing action, and having a closelytextured surface skin formed by the compacting of the surface fibers oi.the mass interspersed with the materials displaced by the gelatinizingaction of the fibers. I 22. As an article of manufacture, a distendedfibrous product in the form of a dried layer, having the surface textureof the fibers modified as a result of a gelatinizing action, the fibersbeing held in open mesh distended relation to one another by thecoalescence of the surface materials displaced by the gelatinizingaction, the fibers being modified by the inclusion of a water proofingagent.

23. As an article of manufacture, a distended fibrous product in theform of a dried layer, having thev surface texture of the fibersmodified as a result of a gelatinizing action, the fibers being held inopen mesh distended relation to one another by the coalescence of thesurface materials displaced by the gelatinizing action, and having aclosely textured surface skin formed by the compacting of the surfacefibers of the mass interspersed with the materialsdisplaced by thegelatinizing action of the fibers, the fibers being modified by theinclusion of a water proofing a ent.

24. The process of treating fibrous material in the production of adistended fibrous product which consists in subjecting the fibrousmaterial to a gelatinizing process in a liquid bath to soften thesurfaces of the fibers, subjecting the fibers to a fireproofingtreatment, distendingthe fibers by the use of a foaming agent capable offorming a foam in the presence of the prcofed fibers, agitating themixture to form bubbles distributed throughout the mass, and drying themass with the fibers in distended relation to one another.

25. The process of treatingfibrous material in which consists insubjecting the fibrous material to a gelatinizing process in a liquidbath to soften the surfaces of the fibers, subjecting the fibers to afireproofing treatment, distending the fibers by the use of a foamingagent capable of forming a foam in the presence of the proofed fibers,agitating the mixture to form bubbles distributed throughout the mass,drying the mass with the fibers in distended relation to one another,and in subjecting the fibers during the drying operation to an actiontending to compact the surface fibers in formation with a closelytextured surface skin.

r 26. 'The process of treating fibrous material in the production of adistended fibrous product which consists in subjecting the fibrousmaterial to a gelatinizing process in a liquid bath to soften thesurfaces of the fibers, subjecting the fibers to a fireproofingtreatment, distending the'fibers by the use of a foaming agent capableof forming a foam in the presence of the proofed fibers, agitating themixture to form bubbles distributed throughout the mass, drying the masswith the fibers in distended relation to one another, and in subjectingthe fibers during the drying operation to sufiicient suction to compactthe surface fibers in formation with a closely textured surfac skin.

:other by the coalescence of the surface materials I displaced by thegelatinizing action, and having a closely textured surface skin formedby the compacting of the surface fibers of the mass interspersed withthe materials displaced by the gelatinizing action of the fibers, thefibers being modified by the inclusion of a fireproofing agent.

FRANK L. BRYANT.

